If you want to see what people do carry on their rigs, look up overweight in the truck camper section. There are many people there that take different approaches to exceeding the GVW, and the trucks carry the loads quite well.
I know because I was one. But then again, I started with a one ton truck, not a half ton truck. You start getting into trouble mostly with the ability to control the weight behind you, and when that goes out of whack, then what started as a nice day can end up a lot more serious.
Axles are rated to carry a certain amount, but the rating of an axle is usually based on the original tires. The same truck can have different axle ratings because one had tough tires, and the other has dressy tires.
You can add springs, get stronger brakes, get a top quality hitch, change wheels and tires... or get a bigger truck.
